Messages in this thread | | | Date | Thu, 26 Sep 2002 12:26:40 -0600 (MDT) | From | Thunder from the hill <> | Subject | Re: [PATCH][2.5] Single linked lists for Linux, overly complicated v2 |
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Hi,
On Thu, 26 Sep 2002, Rik van Riel wrote: > INIT_SLIST_HEAD still has the old behaviour...
I'm now after both behaviors...
#define INIT_SLIST_HEAD(name) \ (name->next = NULL)
#define INIT_SLIST_LOOP(name) \ (name->next = name)
> > +#define slist_add_front(_new_in, _head_in) \ > > > +#define slist_add(_new_in, _head_in) \ > > These two seem to be exactly the same, surely you only need one ?
No, they're not.
(tab-width=8)
slist_add |-------------------------------| | head -> after | | | | new | |-------------------------------| new->next = head->next | head -> after | | ^ | | new | |-------------------------------| head->next = new | head -> new -> after | |-------------------------------|
slist_add_front |-------------------------------| | head -> after | | | | new | |-------------------------------| new->next = head | new -> head -> after | |-------------------------------| head = new | head -> next -> after | |-------------------------------|
(Just to have something drawn...)
> > +#define slist_del(_entry_in) \ > > And what happens when you try to remove an entry from the middle > of the list ?
Well, I can only try to preserve the pointer target, since I don't have a previous entry. (Thus the overly complicated slist_del.)
> Also, how do you know which list the entry is removed from ?
It's the one which previously contained it...
I don't know whether I should like the list header aproach.
It's not bad for either circular lists or such which will have to be gone through only once, as using slist_pop().
> Not having the head of the list in a known place (ie. a fixed > list head) can make a list very hard to find.
But you see we have the problem that there is no such thing as a predeclared structure for it. The only thing we can rely on is a chain of structures which alltogether have a ->next field pointing to another structure of presumably the same type.
> You forgot to rename this define.
Yes, I've forgotten two things there. They are fixed in my file, which I won't post right now (in order not to pollute the list too much with patches. It's that fix plus a forgotten _in.)
> > If you have any objections (apart from who I am), tell me > ^^^^^^^^^^^^^^^^^^^ > I guess that's why we have whois ;)
Oh, that was just for Jes Soerensen, who kept asking.
Thunder -- assert(typeof((fool)->next) == typeof(fool)); /* wrong */
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